package com.msb;

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

import java.io.IOException;

public class WcReduce  extends Reducer<Text, IntWritable, Text, IntWritable> {

    /**
     * key，是一组相同单词kv对的key
     */
    @Override
    protected void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {

        int count = 0;

        // 1 汇总各个key的个数
        for (IntWritable value : values) {
            count += value.get();
        }

        // 2输出该key的总次数
        context.write(key, new IntWritable(count));
    }
}
